Sealed coupling



Jan- 24, 1933. J. H. DENNEDY l 1,894,943

' SEALED couPLING Filed April 25, 1928 t 1 {l/imi E( germ@ Jan. 24, 1933. J. H. DENNEDY 1,894,943

SEALED coUPLING Filed April 25, 1928 2 Sheets-Sheet 2 Patented Jan. 24, 1933 UNITED STATES PATENT OFFICE JAMES "'H. DENNEDY, OF SPRINGFIELD, MASSACHUSETTS, ASSIGNOR TO ROTOBITE CORPORATION, OFCHICAGO, ILLINOIS, A CORPORATION 0F ELINOIS y f SEALED courmne Application led April 25, 1928.A Serial No. 272,685. 4

This:v invention relates to sealed couplings and it pertains more particularly to sealed couplings as applied to the compressor of a refrigeration machine.

The object of my invention is to prevent compressed gases from escaping around the shaft ofthe refrigerant compressor.

A further object is to provide an improved coupling for securing the drive shaft to the compressor shaft.

A further object is'to provide a means for hermetically sealing a coupling on the compressor shaft. p

A further object is to provide 'a conduit from the low pressure side of thecompressor to a hermetically sealed space around the shaft whereby gases escaping around said shaft are sucked back into the compressor.

A further object is to provide a sealed coupling combined with a lubrication system.

Other objects will be apparent as the deftailed description of my invention roceeds.

In the vaccompanying drawings w ich represent preferred embodiments of my invention and in which similar parts are designated by like reference characters throughout the several views,

Fig. 1 is a vertical section through my improved compressor substantially along the lines 1-1 of Fi 2 (this figure shows both the improved scale coupling and the lubrication system) Fig. 2 is a transverse section along the lines 2-2 of Fig. 1; v

Fig. 3 is a vertical section of another embodiment of my sealed coupling the section being taken along the lines 3-3 of Fig. 4; and

Fig. 4 is a transverse section taken along the lines 4-4 of Fig. 3.

Referring to Figs. 1 and 2, my compressor comprises a base plate or casting 10 secured to compressor end plate 11, compressor cylinder 12, compressor endplate i13`and cap plate 14, all of which parts are securely held together and in alignment by suitable bolts 15. A casing '16 is secured to the plate 10 by suitable bolts 16, this casing being adapted to contain oil for the compressor.

The compressor which I have illustrated is of therotary sliding vane type. In the space 17 of compressor cylinder-12 there is eccentrically mounted a cylindrical rotor 18 carrying a plurality of sliding vanes 19, the vanes preferably being oppositelydisposed and held against the compressor walls by spacing rods 2O or suitable sprin means. rlhese vanes are preferably provided with slots adapted to catch and hold oil for perfecting the seal between the vanes and the compressor walls.

The cylindrical rotor 18 is 'centrally mounted on a shaft 21 rotatable in bearing 22 in end plate 13, the end of the4 shaft pro-1 jecting into a clearance space 23 in the cap plate 14 as shown in Fig. 1. The other end of cylindrical rotor 18 is mounted on a shaft 24 which rotates in bearing 25 in the compressor end plate 11. It is understood, of course, that shafts 24 and 21 may be integral and may extend through the cylindrical rotor or the shafts and rotormay be cast together as a unit. l One end of an extensible metal tube 26, preferably of corrugated brass, is secured to end plate 11. by means of an annular ring clamp 27 adapted to be forced against the end plate b screws 28, a suitable gasket 29 preferably eing used to prevent the escape of gases at this joint. The other end of the extensible tube 26-is secured to a collar 30 which holds a friction ring 31.

A coil spring 32 is spaced between the extensible tube 26 and the shaft 24, one end of the spring bearing against end plate 11 and the other end of the spring bearing against a shoulder on the collar 30, the spring tending to urge the collar` and friction element away from end plate 11.

A second 'friction ring 33 is held by a collar 34 and urged against the first friction as shown in Fig. 1. One of the friction rings is preferably of hard metal, such as steel, and the other is preferably a soft friction ring, such as bronze.

vIt will be evident from the above description that any gas which leaks around shaft 24 will be retained in the space which is her.- metically sealed by expansible tubes 26 and 38, the only possible escape for the gas being the joint between friction rings .31 'and 33, which frictionvrings become more gastight with use.

The compressor shaft 24 is tapered at 39 L and the end 'of shaft 24 is provided with threads 40. The driving shaft 37' is rovided with an aperture, .the outer part o whlch has a. tapered portion 41 corresponding to the taper 39 of shaft 24 and the .inner part of this aperture is tapped, that is, is pro- Ivided with threads 42 to engage with the threads on the end of shaft 24.

It will be apparent that as the driving -shaft 37 rotates the engaging threads 491and .42 will tend to pull the tapered portions 39 i4`Dearin 43 and cylinder 44. The oil from the en 'of the bearing d ri s inthe compartment 49 which is sealed y a cap plate 50, the compartment 49 draining into oil-well 46 throu h a hole 51in cylinder 44';v

The oileaves the compressor with the compressed gases through aperture 52 and the aligned passageways 53l (the outer end of the openlng 52 being plugged as at 52'). The foil is-separated from til 0 ture `by any suitable means, and the l0111s returned by a pipe 54 leading through a :valve 55 and pressure gauge 56 to the oilmain 57. The. end plates 11 and 13 are pro'- vided withbores 58 .(their outer ends being A .sealed by'plu inder is provlded with a bore-59 (the end of 58') and the compressor cylwhich is closed by plug 59') .y

Bores 58 communicate with an aperture 60 in the bearings 22 and 25. The oil supplied underl pressure through this aperture 1s ,forced around the bearing and is caught ina horizontal slot 61 spaced about 3409 from the a erture 60. The slots 61 communicate with s ots 62 extending downwardly in the`end 'lltes 11 and 13, as shown in Figs. 1 and 2. e bore 59 communicates with the opening 17in the compressor.

The inlet or suction side of my compressor is a passageway` 63 which corresponds to pas'- sageway 53, shown in Fig. 1, this passageway communicating with space 17 through' an openin 64, the outer end of which is closed by l p 11g 6424 The modification illustrated in Fi 3 and 4 is substantially the same as that a ove described exce t that end plate 11 is made integral with t e frame or castingplO and the earing 25 is provided with'an annular rotruding friction shoulder or ring 31 w ich takes the place of ring 31 of Fig. 1 and which obviates the use of tube 26, ring 27, bolts 28, Y etc. Besides being more economical, this modification has been found to be more easil assembled and to be a more satisfactory sea Theoperation of myv-invention may be the vane has passed opening 59 and that the space'with which bore 59 communicates is always at relatively low pressure. Also, the slot or conduit 61 communicates with the interior of the compressor atthis low pressure side, the slot 61 leading into slot 62 for distributing the oil along the ends of the vanes: It,should be noted vthat the slot or conduit 61 serves two very important functions: it

provides a distributor and an outlet for used oil, an essential element ofthe lubrication system, and it lrovides a means for conduct ing from t e sealed s ace'surrounding the s aft'to the suction or ow pressure side off the compressor.

Gas will inevitably'lealr around the shaft,-

especially from the h1 h pressure side. gas accumulating in t e sealed space around the shaft will build up ai ressure which may deform or rupture the thm brass tube unless something is done to relieve this pressure. Conduit 61 performs this function.

It should also be noted that this conduit revents the gas .from escaping between riction elements 31 and 33 since the ressure of this gas is maintained at substantially atmospheric pressure. Conduit 61 also serves to remove any oil which may find its way into the sealed chamber around the shaft. 'While I have described a preferred embodiment of my invention, it is understood that I am not limited to the details therein set forth except as defined by the following claim.

.Iclaimz The combination with a compressor comprising a fcom ressor casing, a compreor shaft journal i in the casing and extending out through a wall thereof, the com reor shaft outwardly of the wall being 1n two parts, a pair of relatively rotatable co-operating sea ing members, one carried by the casing and the othermounted on one portion of the shaft, a flexible metallic bellows one end of which is sealed to the shaft mounted sealing member and the other end of which is sealed to the other shaft member,- of means for aligning the shaft mounted sealing` member and the second shaft portion to mmimize the flexing of the bellows during rotation, comprising a taper joint for the shaft portions which joint is located within the belows.

In witness whereof, I hereunto subscribe my name this 21st da of April, 1928.

JA S H. DENNEDY.

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